Question

1. Suppose that hemoglobin in the blood should be 12 for a person not to be anemic. It is suspected that a certain population of children has an average hemoglobin level less than 12 (and therefore is anemic on average). A random sample of 50 children from this population gave a sample mean of 11.3 and a standard deviation of 1.6.

a).2pts. State the null and alternative hypotheses.

b). 3pts.Compute the value of the test statistic.

c). 2pts.What is the critical value?

Answer 1

This hypothesis test is a left tailed test .

(a)

The null and alternative hypothesis is

H₀ : = 12

H_a : < 12

(b)

Test statistic = z

= ( - ) /    / n

= (11.3 - 12) / 1.6 / 50

= -0.41

Test statistic = -0.41

(c)

Critical value at 5% level is -1.645